Bristol-Myers Squibb Co. (BMY) ended development of an experimental Alzheimer’s disease treatment after the drug was shown not to be effective, the company said. The drug, avagacestat, was in the second of three phases of clinical development needed for U.S. regulatory approval. Bristol-Myers, based in New York, said data from a completed trial of the drug and a current study showed the therapy wasn’t effective enough to move into the final phase. “No new safety issues emerged in this interim analysis; however, the efficacy observed did not justify further development when evaluated in the context of all avagacestat data,” the company said in a statement. Alzheimer’s is a neurodegenerative disease that robs patients of their memory and ability to function. It affects 5.4 million Americans, according to the Alzheimer’s Association, and is the sixth-leading cause of death in the U.S.